On the performance of carbon fiber structural batteries with temperature

Abstract

Carbon fiber structural batteries, which combine structural and functional properties, have good energy storage capacity while bearing loads have received attention from scholars at home and abroad in recent years as a new type of energy storage device. However, in the process of use, temperature changes will lead to the occurrence of thermal stresses, which may cause structural failure under multiple cycles. In this paper, the thermal-stress coupled model of structural batteries was established first using the temperature and thermal stress models of structural batteries, considering the heat exchange with the external environment of structural batteries. Then based on the coupled model, the thermal stress in the structural battery was simulated and analyzed in COMSOL considering different charge and discharge rates and ambient temperatures of the structural batteries. The results show that: (1) The higher the charging and discharging rates, the higher the temperature of the structural battery, resulting in greater thermal stress. (2) The higher the ambient temperature of the structural battery, the longer its discharge time and the lower the voltage at which discharge terminates, which is beneficial for the electrochemical performance of the battery. But the higher the ambient temperature, the greater the temperature change inside the structural battery, which is not conducive to the mechanical performance of the structural battery. This study can provide reference for the safety analysis of structural batteries in thermal environments.